This invention relates, in general, to optical devices, and more particularly, to molded slotted optical switch structures.
Slotted optical switch devices are well known and widely used in non-contact switching applications. Typically, slotted optical switches comprise a single, separate housing with discrete input and output devices inserted into the housing. The housing typically has a "u" shape with the input device in one upward portion of the housing and with the output device in the other upward portion of the housing. The two upward portions have a slot between them. The input and output devices are aligned so that switching occurs, for example, when an opaque object passes through the slot interrupting optical communication between the input and output devices.
Present discrete component slotted optical switches have several disadvantages including a high cost. The high cost comes from multiple piece parts that are expensive and the required labor to put the multiple piece parts together. Also, additional labor is required to make sure the input and output devices are in proper alignment. In addition, these devices are susceptible to moisture related failures.
One prior art optical switch comprises a single molded structure. This single molded structure has several disadvantages including complex molding techniques, poor yields, and long manufacturing cycle times. These disadvantages result in high manufacturing costs and long customer delivery lead times. Also, it is very difficult to manufacture lenses over the input and output devices in a single molded design. In addition, because the structure is a single unit, a manufacturer cannot use materials optimized for the input side and the output side. This impacts device performance because the materials that aid in the filtering of ambient light on the output side also attenuate radiant energy from the input side.
As is readily apparent, a slotted optical switch structure is needed that overcomes at least the above disadvantages.